<!DOCTYPE html>
<html>
	<head>
		
		<title></title>
		<style type="text/css">
			body{
				margin: 0px;
				height: 100%;
			}
			html{
				height: 100%;
			}
			div{
				width: 90px;
				height: 20px;
				border:1px solid red;
				padding: 20px;
				/* padding:20px 0px 0px 0px;
				 */
				background-color: #FF0000;
				/* margin:50px; */
				/*margin:0px 0px 0px 500px;*/
				/* margin-left:500px ; */
				/* margin-right:
				margin-top:
				margin-bottom:
				padding-left:
				padding-right:
				padding-top:
				paddng-bottom: */
				margin:auto  auto auto auto;
				margin-top:351px;
			}
		</style>
	</head>
	<body>
		<div  >第一个div</div>
		
	</body>
</html>